An interesting discussion on the Connect Forums prompted me to summarise this in my blog, right here. The issue is that the PST Migrations (Client Driven) had appeared to have stopped. The log file on the PST Migration task on the server showed nothing had happened.

It turned out in the end that the end user had turned on RPC/HTTP (aka Outlook Anywhere). When that is enabled, there is a part of the Desktop Policy settings for the user called RPC over HTTP Restrictions which come in to play. That policy setting can be one of :

None -> there are no restrictions even when connecting via RPC/HTTP

Disable User Extensions -> no buttons, nothing works

Disable Vault Cache -> you won’t get vault cache synch’s.

Disable PST Import -> Stops PST migrations happening

Disable Vault Cache and PST Imports -> Combination of the last two.

This particular user had Disable User Extensions set, and after a brief bit of testing you can see in the client trace that “nothing” is activated on the client side. Essentially everything is disabled – like it says :

14/07/2011 14:54:26.522[3552]: DIALOG: ~DialogThread::DisplayDialog

14/07/2011 14:54:26.522[3552]: Policy has disabled client from running when Outlook is configured to use RPC over HTTP

14/07/2011 14:54:26.522[3552]: ~DialogThread::DisplayStartupWarnings

14/07/2011 14:54:26.523[3552]: An exception occurred: Enterprise Vault add-in disabled due to a problem with the current configuration.

One thing that you do have to remember is that if you change the policy setting to correct this, then the mailbox has to be synchronised again, and the user will need to restart Outlook. Also worth remembering the fact that the Outlook Addin can not tell HOW you’re Outlook client is connected to Exchange. It can tell the type of connection, eg offline, disconnected, cached, online, drizzle, etc, but not whether it’s TCP/IP or HTTP. So the addin uses the following “check box”.. via the registry :

Basically if that is ticked, the client will go to RPC/HTTP mode (ie HTTP client) and you will be constrained by the RPC over HTTP Restrictions policy.